Neutron Coincidence Collar, N2023-M

The ANTECH N2023-M Neutron Coincidence Collar (NCC), similar in specification to the ANTECH N2044 Neutron Coincidence Collar (NCC), is used by safeguards inspectors to verify the fissile material content of fresh BWR nuclear fuel assemblies.

It is a high efficiency neutron detector and is used to verify all types of un-irradiated light-water reactor fuel and fuel assemblies, notably LEU fuel, Mixed Oxide (MOX) fuel, fuels containing burnable poisons such as gadolinium, and other contemporary fuel and fuel assembly types.

It employs the classic “collar” geometry and is designed for non-active measurements.

Each unit is supplied with the following components: coincidence collar assembly, cadmium curtains, interrogation source holders, interrogation source holders, interconnection cables, cart and transportation cases.


N2023 Datasheet

Features & Benefits


  • Chamber can be configured for the passive measurement of plutonium content in MOX fuel assemblies and active measurement of Boiling Water Reactor (BWR) fuel assemblies
  • 3 detector panels and one moderator panel housing the interrogation source
  • 1 set of easily removable cadmium moderator panels, 0.50 mm (0.019in) thickness. They are also available in the following configurations, 0.30 mm (0.011in), and 0.35 mm (0.013in) thicknesses
  • Junction box providing a high voltage (HV) connection to ³He detectors and low voltage (LV) and signal connections to Amptek A111 amplifiers. The door panel has two A111 amplifier units, and each side has one A111 amplifier
  • Junction boxes/amplifiers are “daisy chained” together to provide a single signal output to counting electronics, e.g. ANTECH Model 1003 TCA, ANTECH model N2000 Universal Neutron Counter (UNC)
  • 1 TTL output channel (SIGNAL) when used in “OR” counting mode
  • Hinged door to facilitate quick loading



  • 23 highly moderated ³He neutron detectors to maximise efficiency
  • 1 holder is provided for americium/lithium source for active measurements; source holder assembly is easily removable
  • Non-interchangeable connector types prevent misconnection
  • Instrument can be used with the ANTECH Model 1003 TCA or JSR-12, JSR-14, JSR-15 Neutron Coincidence Counter or ANTECH Model N2000 UNC, all with INCC-32 Software
  • Mobile cart provides mounting platform and folds flat for transportation
  • Spares and tool kit available
Outer Dimensions (HxWxD) 510mm x 410mm x 355mm (including connectors)
BWR fuel assemblies 165mm x 165mm (6.50 inches x 6.50 inches)
Maximum Weight (excluding trolley) 37.5kg (with 0.5mm cadmium curtains fitted)
Trolley Weight 15kg
Power to Junction Boxes/Amplifiers 5V DC ± 10%
Maximum Power LV -5VA
Maximum High Voltage HV – 1.8kV
Detection Efficiency With Cd 17%
Without Cd 19.5%
Die Away Time With Cd 40μs
Without Cd 45μs
Output Pulse Width 50ns ± 5ns
Sensitivity 5 x 104 electrons (nominal)
Period between consecutive pulses 500ns
Junction Box IP Rating IP65
Temperature Range Operation 5°C – 40°C, 20% to 95% RH
Storage 0°C – 60°C, 20% to 95% RH
EMC Complies with 2004/108/EC